I will incline mine ear to a parable:
I will open my dark saying upon the harp.
Wherefore should I fear in the days of evil,
when the iniquity of my heels shall compass me about?
They that trust in their wealth,
and boast themselves in the multitude of their riches;
None of them can by any means redeem his brother,
nor give to God a ransom for him: (...)
That he should still live for ever, and not see corruption.
For he seeth that wise men die,
likewise the fool and the brutish person perish,
and leave their wealth to others.
Their inward thought is, that their houses shall continue for ever,
and their dwelling places to all generations;
they call their lands after their own names.
Nevertheless man being in honour abideth not:
he is like the beasts that perish.
This their way is their folly:
yet their posterity approve their sayings. Selah.
Like sheep they are laid in the grave;
death shall feed on them;
and the upright shall have dominion over them in the morning;
and their beauty shall consume in the grave from their dwelling.
But God will redeem my soul from the power of the grave:
for he shall receive me. Selah.
Be not thou afraid when one is made rich,
when the glory of his house is increased;
For when he dieth he shall carry nothing away:
his glory shall not descend after him.
Though while he lived he blessed his soul:
and men will praise thee, when thou doest well to thyself.
He shall go to the generation of his fathers; they shall never see light.
Man that is in honour, and understandeth not, is like the beasts that perish.
A psalm containing some of the most moving lines of poetry in the language. Some of the simplest and deepest of human understanding of the 'natural' human condition in this world, without Christ; and the sense of yearning this understanding evokes.
But what is the nature of death and eternal life for a Christian?
This took me some considerable time to sort-out, even approximately - since there are different ideas in different denominations.
As I understand, very briefly:
When we die from this world, our souls become separated from our bodies and continue. At, or just after, death there is a 'choice' given to these souls about what condition they will dwell in, in the immediate future (first judgment). What determines that choice is Pride versus Love: the Prideful soul ultimately gets what it wants - itself; the Loving soul gets that which it Loves. At the second judgment, a new world is made and the Loving soul is resurrected (soul reunited with its, perfected, body) and dwells with its Love.
[Note: The above paragraph may seem redundant, or too brief or too abstract to be of much value, but I include it because until I became a Christian I didn't understand Christianity to have these beliefs. On the off-chance that other non-Christian readers have similar misconceptions as my former-self, I thought it work putting in this brief statement.]